The<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mi mathvariant="normal">B</mml:mi><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>11</mml:mn></mml:mrow></mml:mmultiscripts><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mi>p</mml:mi><mml:mo>,</mml:mo><mml:msub><mml:mi>α</mml:mi><mml:mn>0</mml:mn></mml:msub></mml:mrow><mml:mo>)</mml:mo></mml:mrow><mml:mmultiscripts><mml:mi mathvariant="normal">Be</mml:mi><mml:mprescripts/><mml:none/><mml:mn>8</mml:mn></mml:mmultiscripts></mml:mrow></mml:math>reaction at sub-Coulomb energies via the Trojan-horse method

The $^{11}\mathrm{B}(p,{\ensuremath{\alpha}}_{0})^{8}\mathrm{Be}$ reaction was studied from $1\phantom{\rule{0.3em}{0ex}}\text{MeV}$ down to astrophysical energies by means of the Trojan-horse method applied to the $^{2}\mathrm{H}(^{11}\mathrm{B},{\ensuremath{\alpha}}_{o}^{8}\mathrm{Be})n$ three-body reaction performed at an incident energy of $27\phantom{\rule{0.3em}{0ex}}\text{MeV}$. Coincidence spectra measured in a kinematically complete experiment show the presence of the quasifree $^{11}\mathrm{B}\penalty1000-\hskip0ptp$ process. The astrophysical factor $S(E)$ for the $^{11}\mathrm{B}(p,{\ensuremath{\alpha}}_{0})^{8}\mathrm{Be}$ reaction was extracted from the three-body cross section at low neutron momentum. The result was compared with the behavior of the astrophysical factor from the directly measured two-body reaction.